On Mon, Nov 23, 2015 at 04:22:08PM +0200, Ville Syrjälä wrote: > On Sat, Nov 21, 2015 at 10:51:50AM +0000, Chris Wilson wrote: > > On Fri, Nov 20, 2015 at 10:09:18PM +0200, ville.syrjala@xxxxxxxxxxxxxxx wrote: > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > We still get spurious pipe underruns on ILK/SNB/IVB under two > > > circumstances when dealing with PCH ports: > > > * When the pipe has been disabled, but FDI RX/TX is still enabled > > > * During FDI link training > > > > > > Both cases seem to happen at least when we do VGA+HDMI cloning > > > from the same pipe. I don't think I've seen them when not cloning, > > > but can't be 100% sure. > > > > > > Disable underrun reporting around those places to eliminate the > > > dmesg errors. > > > > > > Testcase: igt/kms_setmode/basic-clone-single-crtc > > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Acked-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > > I wondered if logging the suppressed errors would be of any use? > > Hmm. Maybe just to confirm that they still happen, and thus suppressing > is still neded. > > > Does > > the check_cpu_fifo work if the reporting is disabled? Could we do a > > manual check and DRM_DEBUG_KMS() if the enable did generate a failure. > > If the check_cpu_fifo does work, won't we still get the error from the > > added check in atomic_commit()? > > The check only looks at pipes that have underrun reporting enabled. I > suppose it might be possible to have it check all the pipes. At the > point where we call it no explicit suppression should be happening, so > the only reason why underrun reporting would be disabled on any pipe is > due to detecting a previous underrun via the interrupt. Does the hw flag the underrun even if the interrupt is disabled? (Playing games with PIPESTAT_IER?) Could we then report (debug) that an underrun happened before we re-enable reporting? -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
